For exterior vinyl fencing products, exterior colors are typically limited to white, since dark colors absorb substantial amounts of solar radiation which can cause undesirable heat rise within in the materials. In fencing materials this heat rise can cause excessive thermal expansion on the side of the fence that is exposed to the sun's rays. This thermal expansion is often substantially greater than the expansion on the opposite, shaded, side of the fence, and the differential expansion can result in unsightly bowing of the fencing members. For decking materials, which may not be subject to the same bowing problems as fencing materials, external colors are still limited to light colors since the surface of a dark-colored decking materials can absorb significant quantities of solar radiation and thus can be too hot to walk on in bare feet during a hot summer day.
Dark colored vinyl materials also often suffer from inferior weatherability and durability when exposed to outdoor environments due to the adverse interaction between the vinyl material and the near infrared (near IR) rays emitted by the sun.
IR reflective paints are known for use in minimizing heat absorption through surfaces exposed to the sun. Such paints typically incorporate a metallic oxide system pigment having a high reflectance of IR rays, such as titanium oxides, mixed metal titanates, iron oxides, barium oxide, and the like. Such paints are applied to the target object to form an IR reflective coating. IR reflective paints suffer, however, from the problem that only a limited range of colors may be produced, and desirable dark colors cannot practically be provided. Additionally, paint systems suffer from problems of poor adhesion and scuff or scratch resistance, and when the paint coating is degraded, the IR reflectance is compromised.
Thus, it would be desirable to provide a material coating or composition for use in manufacturing exterior building products in a wide range of highly-desirable outer surface colors—particularly dark colors—in which solar heat absorption is minimized, thus minimizing or eliminating the aforementioned problems.